Currently, insulin can only be given by injection. Pfizer, Inc., and Inhale Therapeutic Systems, have developed a dry powder insulin formulation and aerosol delivery device that safely delivers a rapid acting insulin by forming an insulin cloud that patients can inhale into their lungs where it is then absorbed. Since chronic inflamation or a decrease in pulmonary function can reduce the tolerance and bioavailability of inhaled medications, this study will measure changes in the moderate to severe asthmatic.